Method predict_scale_level

src/PLPSLAM/data/landmark.cc:319–340

____ Nearer /____\ level:n-1 --> dmin /______\ d/dmin = 1.2^(n-1-m) /________\ level:predicted --> d = cam_to_lm_dist /__________\ dmax/d = 1.2^m Farther /____________\ level:0 --> dmax log(dmax/d) predicted_scale_level = ceil(------------) log(1.2)

        // predicted_scale_level = ceil(------------)
        //                                log(1.2)
        unsigned int landmark::predict_scale_level(const float cam_to_lm_dist, const frame *frm) const
        {
            float ratio;
            {
                std::lock_guard<std::mutex> lock(mtx_position_);
                ratio = max_valid_dist_ / cam_to_lm_dist;
            }

            const auto pred_scale_level = static_cast<int>(std::ceil(std::log(ratio) / frm->log_scale_factor_));
            if (pred_scale_level < 0)
            {
                return 0;
            }
            else if (frm->num_scale_levels_ <= static_cast<unsigned int>(pred_scale_level))
            {
                return frm->num_scale_levels_ - 1;
            }
            else
            {
                return static_cast<unsigned int>(pred_scale_level);
            }
        }

        unsigned int landmark::predict_scale_level(const float cam_to_lm_dist, const keyframe *keyfrm) const
        {